Prediction of the Position Error of the Uncertain 3-UPU TPM Using Interval Analysis

Abstract

This paper deals with the prediction of the 3-UPU translational parallel manipulator position error caused by the design parameter uncertainties. An algorithm, based on the interval analysis is developed and used to estimate the distribution of the position error within the robot workspace. As a result, we represented the distribution of the position error in different sections of the workspace and we showed that the minimum of the position error is located in the neighborhoods of base center. In general, the minimum position error is reached for higher sections of the workspace. Moreover, the effect of each design parameter uncertainty on the manipulator precision at different sections of the workspace is discussed. At the extreme points of the workspace, the most influent design parameters on the position error are the leg position angles and the radius of the base and the platform uncertainties. The actuator lengths uncertainties are supposed constant and have no effect on the platform position error.